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        Discussion Measuring discharging output from charger

#1 lynn1953 Jan 31, 2013 08:57 AM

Measuring discharging output from charger
 
I saw somewhere on how to check the actual mah the charger is drawing from the battery during a discharge by putting a voltmeter in between the batt and chrgr. I have seached hi and lo and can't find it again. There was a diagram for the pig tail and I can't recall the details. I think it was actually a calibration check for the charger. If anyone can help I would really appreciate the feedback. I have a accucyle elite and a 306b that I would like to check to see what is actually being pulled from the batt.

#2 grimbeaver Jan 31, 2013 09:55 AM

Why not just put a watt meter between the charger and battery?

Though you have to remember anytime you do a check like this it's only as accurate as the device measuring it.

#3 lynn1953 Jan 31, 2013 10:38 AM

I don't have a wattmeter(yet) but I have an Fma DVM shunt that when connected with a dvm in between a battery and motor will show the amps a motor pulling. I would guess that might work.

#4 grimbeaver Jan 31, 2013 10:39 AM

Quote:

Originally Posted by lynn1953 (Post 23990314)
I don't have a wattmeter(yet) but I have an Fma DVM shunt that when connected with a dvm in between a battery and motor will show the amps a motor pulling. I would guess that might work.

Yep that will work. The charger is no different from a motor, they are both discharging the battery.

#5 mrforsyth Jan 31, 2013 10:49 AM

A shunt / DMM will register current (mA, A) but has no ability to record capacity (mAh, Ah).

#6 lynn1953 Jan 31, 2013 10:56 AM

Thanks, I I thougth it was logical but I didn't want to let the smoke out of something:eek:

#7 everydayflyer Jan 31, 2013 11:10 AM

Quote:

I saw somewhere on how to check the actual mah the charger is drawing from the battery during a discharge by putting a voltmeter in between the batt and chrgr.
Any decent charger with a LCD dispaly will show the mAh removed from the battery during a discharge jusr rge same as they show mAh delivered to the battery during a charge.


See graph and text here

http://www.rcgroups.com/forums/attac...mentid=4165842

Note charge stated at Storage Level.

Charles

#8 lynn1953 Jan 31, 2013 11:39 AM

Thanks Charles. I was just curious if the chargers would match close to what the charger was telling me. What is bugging me more than anything is how I can stumble across something doing a search and can never seem to retrace my search to find it. :)

#9 touche Jan 31, 2013 11:59 AM

LOL..I have a whole book of bookmarks on stuff I stumble across.


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